Once upon a time, analysts, pundits and historians explored the relationship between a given subject and his father. We do so for possible insight into the subject’s values, character, decision-making process, biases, interests, fears, etc. You know — acorn, tree.

But the standard intellectual inquiry, for some reason, does not apply to the long, intimate relationship between Barack Obama and the Rev. Jeremiah Wright, who called himself a “second father” to young Barack.

Sen. Obama described his 20-year relationship with his pastor this way: “What I value most about Pastor Wright is not his day-to-day political advice. He’s much more of a sounding board for me to make sure that I am speaking as truthfully about what I believe as possible and that I’m not losing myself in some of the hype and hoopla and stress that’s involved in national politics.” Indeed, Obama describes a relationship that is closer, far closer than the relationship that many sons have with their fathers.

Leftist New York Times columnist Maureen Dowd confidently places the actions, policies and decisions of George W. Bush at the feet of his father. Dowd insists, for example, that George W. Bush’s decision to invade Iraq was Dad-driven. She called the Iraq War “a Freudian tango” that provided a “chance for W. to complete his transformation from the screwup son to the son who fixed his father’s screwups.” None of that fear of chemical or biological attack in the wake of 9/11 national security stuff for Dowd. No, it’s all about Dad.

In a recent column comparing blue-blooded “patricians” Bush-41 and Mitt Romney, Dowd writes, “Their political philosophies were not shaped by a passion for ideas as much as a desire to serve and an ambition to climb higher than their revered fathers. Pragmatism trumps ideology; survival trumps conviction. Both men, to the manner born in Greenwich and Bloomfield Hills, adapted uncomfortably to the fundamentalist tent meeting mood of the modern GOP, knowing their futures depended on Faustian deals with the right.”

But Obama and Wright’s relationship tells us nothing.

In a column about presidential aspirants and their fathers, Dowd puts the Bush and Romney quartet on the couch: “American politics bristles with Oedipal drama. Sons struggling to live up to fathers. Sons striving to outdo fathers. Sons scheming to avenge fathers. Sons burning to one-up fathers. Sons yearning to impress fathers who vanished early on.

Sons leaning on fathers. Sons using fathers as reverse-play books. …”It’s daunting, so soon after ‘Junior’ Bush crashed the Bush family station wagon into the globe in an effort to both avenge and outshine his dad, to gear up for another Republican presidential candidate (Mitt Romney) whose resume copies his famous Republican father and whose relationship with dad sculpts his outlook.”

But Obama and Wright’s relationship tells us nothing.

About Abraham Lincoln, historian David Herbert Donald writes: “Abraham’s pulling away from his father was something more significant than a teenage rebellion. Abraham had made a quiet reassessment of the life that (his father) Thomas lived. He kept his judgment to himself, but years later it crept into his scornful statements that his father ‘grew up, literally without education,’ that he ‘never did more in the way of writing than to bunglingly sign his own name,’ and that he chose to settle in a region where ‘there was absolutely nothing to excite ambition for education.’ To Abraham Lincoln that was a damning verdict. In all of his published writings, and, indeed, even in reports of hundreds of stories and conversations, he had not one favorable word to say about his father.”

About John F. Kennedy’s relationship with family patriarch Joseph, presidential historian Doris Kearns Goodwin says: “There was no way (Jack) thought he could be what Joe. Jr. had been to his father. So the two of them circled around each other, I think for years, with Jack wanting to satisfy some need of the father’s, the father wishing Jack could satisfy it but the father never could see Jack at that point as a politician.”

Critics blasted Republican former presidential candidate Sen. John McCain for seeking — and then repudiating — the endorsement of a controversial Texas televangelist even though the Rev. John Hagee had never been McCain’s personal pastor, let alone for 20 years.

But one “injects race” by asking simple questions about Obama and Wright. It is no stretch to argue that Wright’s view of economics — that America became successful not because of its founding principles but by exploiting the weak — reflects Obama’s own economic worldview.

Four years ago when Wright belatedly erupted as a possible campaign-ending scandal, Obama called his relationship with his then-pastor “a legitimate political issue.” And Fox News’ Chris Wallace recently said that in retrospect “McCain was crazy” not to use this issue.